Magnetic Field Calculation

i_lower=2
1_upper=4
B=10^-7i*(cosθ1+casθ2)/d
As magnetic field by each wire is just diff. in direction and proportional to i.The magnetic field by lower(reflection) is cancelled,and net current can be assumed as 2 in upper and 0 in lower.
B net=3*(10^-7*2*(1/2+1/2)/√3)=2√3*10^-7
B⁰=2

thanx swaraj , i had taken d = 1√3 by mistake.